“A man who can't putt is a match for no one; a man who can putt is a match for anyone.”
Putting is considered one of the most important aspects of golf to master and you can practice your swing anywhere. If your putting game could use some polishing, try these quick tips to improve your golf swing in no time:
When putting, the placement of your fingers matters more than ever. Keep your thumbs flat on the top of the putter’s grip and your index finger under the shaft. This will provide you with more "touch" during your putt since you can control your stroke using your shoulders rather than your wrists.
Poor posture while putting can create a poor, inconsistent swing. Stand as if your heels, shoulders, head, and butt were all leaning flat against a wall. Keep your feet shoulder width apart and bend at your hips to lean over the ball.
Excess wrist movement leads to a wobbly putt. To prevent this, keep in mind that you have to maintain the “triangle” that is formed by your arms and shoulders when you enter your putting stance. This triangle should be maintained from the start of your swing all the way through to the follow-through.
If you wish to practice limiting the movement of your wrists, you can try using the “ruler drill”. Use a band or your wrist watch to secure a ruler along your wrist. When your putting mechanics break down, you will feel the ruler exert pressure on your wrist or hand. Keep practicing until you no longer feel this pressure.
Basics of Putting, PGA.com